The Ancient Yak (Bos Primigenius)
The Ancient yak is not really a yak at all, but rather an ancestor of the yak and various other Bovines. It is quite different from the yak, however it is easy to see how it could have evolved to create the modern Yak.
What made them become extinct?
These animals did not become extinct overnight. Their many characteristics merely got amplified by the process of natural selection. They became extinct because as the climate changed, they slowly changed with it until they had formed a whole new species. It different areas of the globe, different characteristics were passed down until hundreds of new species and subspecies were born from this one creature.
Structural Adaptations
The Bos Primigenius (more commonly known as an Auroch) was well adapted to survive in is climate. It had one pair of large horns for fighting of predators such as wolves. It is also thought that they used these horns to assert dominance over other members of their herd. These horns where similar in size and texture to the Yak's, however they were slightly bigger and curved forwards instead of back. Like the yak, they also had a thick coat to deal with cold temperatures as they lived in similar climates. This coat is believed to be similar in texture to the yaks outer hair. As the climate they lived in wasn't as harsh as the climate of the Yak, the Bos Primigenius didn't need as thick a coat. The hair was also a lot shorter and more similar in length to a bison (it was also the ancestor of many breeds of Bison). The Bos Primigenius was far more widespread than the yak and is also an ancestor of the domestic cattle. It is thought that the Bos Primigenius that evolved into the Yak lived in colder parts, as it was quite well spread around.
Behavioural Adaptations
It is difficult to know about the Behavioural adaptations of the Bos Primigenius as it lived a long time ago and there aren't many records of it. It is thought that, like the Yak, they were quite shy and quick to scare. They could run away in a herd, however they did occasionally use their horns to fight off predators such as wolves. It is also thought thst they used their horns to assert dominance over each other and for males to fight for mates. When they charged, their horns could be deadly. They also had a lot of strength which meant that they were domesticated by humans eventually. It is thought that the domesticated Bos Primigenius evolved into modern cattle, while the ones that run wild turned into Bison and various other types of wild bovine, including the Yak.
Physiological Adaptations
The Bos Primigenius had a few physiological adaptations to help it survive. The first one is its slow digestive system. This is extremely similar to the Yak. It slower digestive system means that it can survive on lower quality forage, just like the Yak. Another one of its Physiological adaptations is its quick response to danger. When startled, The Bos Primigenius also sprung into action very fast, whether to run away, or to charge the attacker. It is extremely difficult to assert these things for sure as the animal is long dead and they can's run any tests on it. However by examining its various evolutionary children, it is possible to make an accurate hypothesis of what the physiological adaptations would have been.
Fig 2: A map showing the distribution of the Bos Primigenius
Habitat
As is visible from the distribution map (above), the Bos Primigenius was extremely wide spread throughout the world. This is part of the reason it evolved into so many different types of Cattle and Bison. Its climate varied from very cold to very hot and it spreads across a wide range of different climates. From hot African land to the frigid winters of tibet, the Bos Primigenius evolved to survive in many different climates around the world. Its fur, skin and internal structure all changed to suit the place where it was living. This is why the Bos Primigenius still has ancestors alive. Because it was able to adapt to live in a wide range of different places, giving birth to many new species.
The Ancient yak is not really a yak at all, but rather an ancestor of the yak and various other Bovines. It is quite different from the yak, however it is easy to see how it could have evolved to create the modern Yak.
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Subfamily: Bovinae
Genus: Bos
Species: †B. primigenius
Binomial Name: †B. primigenius
What made them become extinct?
These animals did not become extinct overnight. Their many characteristics merely got amplified by the process of natural selection. They became extinct because as the climate changed, they slowly changed with it until they had formed a whole new species. It different areas of the globe, different characteristics were passed down until hundreds of new species and subspecies were born from this one creature.
Structural Adaptations
The Bos Primigenius (more commonly known as an Auroch) was well adapted to survive in is climate. It had one pair of large horns for fighting of predators such as wolves. It is also thought that they used these horns to assert dominance over other members of their herd. These horns where similar in size and texture to the Yak's, however they were slightly bigger and curved forwards instead of back. Like the yak, they also had a thick coat to deal with cold temperatures as they lived in similar climates. This coat is believed to be similar in texture to the yaks outer hair. As the climate they lived in wasn't as harsh as the climate of the Yak, the Bos Primigenius didn't need as thick a coat. The hair was also a lot shorter and more similar in length to a bison (it was also the ancestor of many breeds of Bison). The Bos Primigenius was far more widespread than the yak and is also an ancestor of the domestic cattle. It is thought that the Bos Primigenius that evolved into the Yak lived in colder parts, as it was quite well spread around.
Behavioural Adaptations
It is difficult to know about the Behavioural adaptations of the Bos Primigenius as it lived a long time ago and there aren't many records of it. It is thought that, like the Yak, they were quite shy and quick to scare. They could run away in a herd, however they did occasionally use their horns to fight off predators such as wolves. It is also thought thst they used their horns to assert dominance over each other and for males to fight for mates. When they charged, their horns could be deadly. They also had a lot of strength which meant that they were domesticated by humans eventually. It is thought that the domesticated Bos Primigenius evolved into modern cattle, while the ones that run wild turned into Bison and various other types of wild bovine, including the Yak.
Physiological Adaptations
The Bos Primigenius had a few physiological adaptations to help it survive. The first one is its slow digestive system. This is extremely similar to the Yak. It slower digestive system means that it can survive on lower quality forage, just like the Yak. Another one of its Physiological adaptations is its quick response to danger. When startled, The Bos Primigenius also sprung into action very fast, whether to run away, or to charge the attacker. It is extremely difficult to assert these things for sure as the animal is long dead and they can's run any tests on it. However by examining its various evolutionary children, it is possible to make an accurate hypothesis of what the physiological adaptations would have been.
Habitat
As is visible from the distribution map (above), the Bos Primigenius was extremely wide spread throughout the world. This is part of the reason it evolved into so many different types of Cattle and Bison. Its climate varied from very cold to very hot and it spreads across a wide range of different climates. From hot African land to the frigid winters of tibet, the Bos Primigenius evolved to survive in many different climates around the world. Its fur, skin and internal structure all changed to suit the place where it was living. This is why the Bos Primigenius still has ancestors alive. Because it was able to adapt to live in a wide range of different places, giving birth to many new species.
Biblliography
Bos Primigenius Primigenius. (2003, April). Retrieved June 29, 2010, from http://www.petermaas.nl/extinct/speciesinfo/aurochs.htm
BBC. (2008, July). Aurochs. Retrieved June 29, 2010, from http://www.bbc.co.uk/nature/wildfacts/factfiles/3037.shtml
Tikhonov, A. (2003). Bos Primigenius. Retrieved June 15, 2010, from http://www.iucnredlist.org/apps/redlist/details/136721/0